Many manufacturing and packaging procedures require that an article, or a series of articles, be rotated or turned to change the physical orientation of the article. For example, an upright box that has exited one step of a packaging procedure, may need to be placed on its side before entering the next step of the procedure.
A number of electrically-powered devices that rotate an article exist. However, these devices have several drawbacks, including complexity, cost of operating and maintaining, and an inability to accommodate changes in the packaging line.
Static or non-electrically powered turning devices are also known in the art. One static article-turning device utilizes a plurality of winding parallel rails which define a path; an article is turned as the article traverses the path. A draw back of this rail-type device is that the rails are typically fabricated from metal and must be aligned with some precision, otherwise the article will jam or fall out from between the rails.
A second type of static article-turning device is taught by U.S. Pat. No. 4,492,299 to McLeod. The '299 patent discloses a device comprising a plurality of cards; each card having an aperture in the general shape of the article to be turned. The cards are placed in succession such that the aperture of each card is slightly skewed from the aperture of the card directly preceding it. In this manner, the cards form a path and the article is incrementally turned by the cards (i.e., by the amount of the skew of each aperture) as the article proceeds along the path. A drawback of this type of prior article-turning device is that the cards must be cut and aligned with some precision; also, the incremental change in the path made by each card tends to grab the corners of boxes causing blockage.